“The Electronics Of Radio” NorCal 40B Transceiver Build Lab Notes: Problem 19A, 19B, 19C, 19D, 19E
This continues a series of blog posts on David Rutledge’s text, “The Electronics of Radio”, that I am studying while building the NorCal 40B transceiver. This series of posts will not be a review of the book, nor is it a assembly manual. Rutledge presents a series of problems at the each chapter that aid in understanding electronics and building the 40M QRP CW transceiver. I am going to try to go through all of these problems and document them here. All of these are titled similarly, so search for them that way. For what its worth, most people will want to skip these posts, they are really for my own self-education on electronics and may not make a lot of sense unless you have Rutledge’s book.
[The links to all problem solutions as I go through them will be posted here.]
A.
Slope = (y2-y1) / (x2-x1) = 0.740V / 23.5µs = 31.49kV/s
B.
Slope = (y2-y1) / (x2-x1) = 0.4V / 100µs = 4kV/s
C.
D.
At 5V, the attenuation of the receiver switch is entirely engaged, with a measured voltage (at 7MHz 10Vpp input signal) is 6.8mV, which is equal to 680µV at 1Vpp. (Note: I should have increased this to 12V and measured at that point to be in keeping with the text.)
On-Off Rejection Ratio = R = 20log( Voff / Von ) = 20log(83mV/680µV) = 41.7dB
E.
Attenuation of Voltage in dB = 20log10(Vin/Vout)
